Photochromic spiroxazines, compositions and articles containing them

ABSTRACT

The invention concerns photochromic compounds having a formula (I), where R 1  is a polycyclo group formed by at least one alicyclic group linked to, bridged or condensed, with at least one other aliphatic or aromatic ring. ##STR1##

The present invention concerns novel compounds of the spiroxazine typepresenting, in particular, photochromic properties. It also concerns thephotochromic compositions and ophthalmic articles (e.g., lenses) whichcontain spiroxazines.

The photochromic compounds are capable of changing color due to theinfluence of a poly- or monochromatic light (e.g., UV) and they arecapable of recovering their initial color when the irradiation withlight stops, or due to the influence of a poly- or monochromatic lightwhich is different from the first light, or due to the influence oftemperature and/or of a poly- or monochromatic light which is differentfrom the first one.

These photochromic compounds are applied in various fields, for example,for the manufacture of ophthalmic lenses, contact lenses, somesunshades, filters, optics for cameras or photographic apparatus orother optical and observation devices, glass partitions, decorativeobjects, display elements or for the storage of information by opticalinscription (coding).

In the filed of ophthalmic optics, and in particular in the field ofeyeglasses, a photochromic lens, comprising one or more photochromiccompounds, must present:

a high transmission in darkness or in the absence of sunlight,

a low transmission (high colorability) when exposed to irradiation bysunlight,

an appropriate kinetics of coloration and decoloration,

a tint which is acceptable to the consumer (gray or chestnut brown,preferably), with, preferably, maintenance of the selected tint duringthe course of the coloration and the decoloration of the lens,

a maintenance of the performances of the characteristics in atemperature range of 0-40° C.,

a significant durability, because the objectives intended aresophisticated, and therefore expensive, corrective lenses.

These lens characteristics are in fact determined by the activephotochromic compounds which, in addition, must be perfectly compatiblewith the organic or mineral support which constitutes the lens.

Moreover, it should be noted that the obtention of a gray or chestnutbrown tint may require the use of at least two photochromes of differentcolors, that is, having distinct maximum absorption wavelengths in thevisible range (λ_(max)). This association thus imposes still otherrequirements on photochromic compounds. In particular, the kinetics ofcoloration and decoloration of the two or more associated activephotochromic compounds must be essentially identical. The same appliesto their stability over time and, also, to their compatibility with aplastic or mineral support.

Among the numerous photochromic compounds described in the prior art,one can cite the indolinospironaphtoxazines described in U.S. Pat. Nos.3,578,602; 3,562,172; 4,215,010; European Patent Nos. 0,171,909;0,313,941; French Patent No. 2,647,789 and European Patent No.0,600,669: ##STR2##

The group R₁ of these molecules represent straight or branched alkyls,alkylaryls or alicyclics. These compounds are considered to meet thespecifications defined above.

In fact, while these compounds have indeed one or more of the basicproperties sought, such as a high transmission in darkness, a highcolorability when exposed to sun radiation, absorption in the blue orviolet (570-630 nm), a rapid kinetics of coloration and decoloration,all the compounds described to this day do not have the completecombination of the wanted properties which is required for theproduction of satisfactory articles which can be manufacturedindustrially.

Whereas the prior art teach how to modify the absorption band by theaddition of substituents to the different positions of the rings and,also, teach how to modify the kinetics of decoloration, in contrast, itdoes not teach how to increase the colorability of these moleculeswithout increasing the residual coloration in the inactivated state and,above all, on how to make them photochemically stable so as to allowtheir use on an industrial scale. Indeed, without a high stability,these expensive molecules, introduced into a sophisticated lens, cannotbe used.

It is the merit of the applicant to have found, unexpectedly, that thepresence of polycyclic groups, preferably bicycloalkyl groups, allowed asolution of the problem of the stability, the residual coloration andthe colorability, which are essential for the above-mentionedapplications.

The originality of the invention resides in the surprising effect of thepolycyclic groups, which increases the colorability of the spiroxazineswithout increasing their residual coloration, while ensuring excellentphotostability.

Thus, the present invention concerns a compound, in particular aphotochromic compound, having the following general formula (I):##STR3## in which, R¹ is a polycyclic group formed by at least onealicyclic group which is linked to bridged or condensed with at leastone other aliphatic and/or aromatic ring, where the rings can optionallycontain at least one heteroatom and at least one unsaturation,

R², R³ are identical or different and they represent an alkyl group,straight or branched, of 1-12 carbon atoms, an alkenyl group, alkynyl,aryl, alkylaryl, cycloalkyl, R² and R³ can, optionally, combine to forma carbocyclic or heterocyclic group having 5 to 10 atoms,

R⁴, R⁵, R⁶ and R⁷ are identical or different and they represent:

hydrogen,

an alkyl, cycloalkyl, alkenyl, alkynyl, aryl (preferably phenyl,naphthyl mono-, -di-, or trisubstituted by electron done or acceptorgroups), heteroaryl, aryloxy or aralkyl, said group being optionallyhalogenated,

a halogen, preferably F, Br, Cl,

OR, SR, --OCOR-, --COOR, with R═H, alkyl and/or cycloaklyl and/or aryl,

a (poly)ether, a (poly)amide, a (poly)carbonate, a (poly)carbamate, a(poly)urea or a (poly)ester,

* an amino radical which gives rise, once it is bound in (I), to aprimary, secondary or tertiary amine, said amine being alkyl, aryl oraralkyl, mono- or disubstituted depending on its nature,

* or an aminocyclic radical containing, optionally, one or moreheteroatoms,

or an electron withdrawing group selected, preferably, from the groupcomprising CF₃, CN, NO₂, SCN,

where at least two of the radicals R⁴, R⁵, R⁶, R⁷, preferably carried bytwo adjacent carbon atoms, can combine to form at least one aromaticring having 5 or 6 members or an aliphatic ring having 5 to 7 members,advantageously 5 or 6 members, said ring(s) comprising, optionally, atleast one heteroatom, so as to form at least one heterocyclic ring, thelatter being optionally substituted by one or more radicals which may beidentical or different, and have the same definition as given above forR⁴ to R⁷,

A represents a (hetero)aromatic ring (containing, for example, at leastone nitrogen atom) and possibly substituted by one or more radicals R⁸,which may be identical or different, and having the same definition asgiven above for R⁴ to R⁷,

n is a whole number and when n≧2, two of the radicals R⁸ can possiblycombine to form at least one aromatic or heteroaromatic ring.

Preferably, R¹ represents a bicyclic group. It is particularly preferredfor R¹ to represent an asymmetric bicyclic group. The asymmetry can bethe result of either the nature of the group or the present of asubstituent(s). Preferred examples of such asymmetric bicyclic groupsare substituted or unsubstituted norbornyl groups.

According to the invention it is possible to consider the substitutionof at least one of the rings of R¹ by at least one substituent R⁹ whichhas the same definition as that given above for R⁴ to R⁷.

Specific examples of groups R¹ are the following: ##STR4## among manyothers.

Preferred compounds of the invention have the following formula (I'):##STR5## where A, and R¹ to R⁷ are as defined above, and B is anaromatic or aliphatic ring having 5 to 7 members, optionally comprisinga heteroatom which may or may not be substituted by one or more radicalswhich may be identical or different, and have the same definition asgiven for R⁴ to R⁷.

According to a particularly preferred embodiment of the invention, ringA is a phenyl group and R⁴ and R⁵ combine to form an annealed aromaticring or a bicyclic aromatic ring condensed with the phenyl group whichbears them. This corresponds to the following formula (I"): ##STR6## inwhich R¹ to R⁴ and R⁶ and R⁸ are as defined above, and n and m assumethe values 0 to 4.

Among the substituents which can be considered for the compounds withformula (I), (I') and (I") according to the invention, groups R⁴ and R⁹must be considered, which comprise and/or form at least one reactivefunction for polymerization and/or crosslinking, selected, preferably,from the following list: alkenyl, advantageously vinyl, methacryloyl,acryloyl, acryloxyalkyl, methacryloxyalkyl or epoxy.

Thus, the photochromic compounds according to the invention can bedesigned as monomers, of different types or not, which can react betweenthemselves or with other comonomers, to form homopolymers and/orcopolymers which carry a photochromic functionality and which have themechanical properties of macromolecules. It follows that one of theobjects of the present, invention are formed by these homopolymers orcopolymers comprised of the (co)monomers and/or by the crosslinkages, atleast in part made up of photochromic compounds (I), (I') and (I")according to the invention.

In the same order of ideas, the above-mentioned compounds (I), (I') and(I") can be considered to be crosslinking agents which have reactivefunctions capable of allowing the formation of bridges between polymerchains of photochromic nature of not. The crosslinked compounds whichcan thus be obtained, also constitute another object of the presentinvention.

In a general manner, in the preceding formulas, the followingdesignations are used, according to the invention:

"alkyl," referring preferably to a straight or branched hydrocarbongroup having from 1 to 12 carbon atoms;

"alkoxyl," referring to a group of O-alkyl type preferably having from 1to 10 carbon atoms,

"aryl," referring to an aromatic hydrocarbon group containing at least 6carbon atoms,

"heteroaryl," referring to an aromatic hydrocarbon group comprising atleast 5 atoms, of which at least one is a heteroatom,

"aralkyl," a group comprising at least one alkyl and at least one aryl,as defined above,

"heteroatom," atoms different from C and H, belonging preferably to thefollowing group: N, O, S and P.

The photochromic compounds which are used particularly preferentially inthe context of the invention thus are, as can be concluded from theabove, indolinospironaphthoxazines or indolinospirobenzoxazines.

The most advantageous indolinospiroxazines include those having theformula: ##STR7## n=0, 1 or 2 and R², R³ =C₁ -C₅ alkyl,

R⁴ =H, OMe,

R⁶ =H, OMe or amino,

R⁸ =H, Me, OMe or CF₃.

It is the merit of the applicant to have disclosed these compounds,because they present particularly advantageous photochromic properties.More specifically, they have a high colorability, particularly in theblue region. They are thus well suited to combination, observingcompatibility and complementarity requirements, with photochromes whichabsorb in the yellow, orange, red and violet, so as to obtain a broadcoverage of the visible absorbance spectrum and thus coloration tintswhich are chestnut brown or dark gray.

The sensitivity, as well as the height and the area of their λ_(max)peaks in the visible, attain satisfactory values.

These compounds are also perfectly stable and compatible with supportmatrixes made of organic polymer or of mineral material, both in a formincluded in the matrix and in the form of a coating.

In solution or in a polymer matrix, the compounds according to theinvention are colorless or slightly colored in the initial state andthey rapidly develop an intense coloration under UV light (365 nm) or alight source of the solar type. Finally, they quickly recover theirinitial color when the irradiation stops.

The compounds of the invention can be obtained by the condensation of anindoline derivative substituted with a polycyclic R¹ group and anaromatic nitroso alcohol derivative such as those described, forexample, in U.S. Pat. Nos. 3,578,602; 4,634,767; 4,913,544 and EuropeanPatent No. 600,669. This reaction can take place in solvents such asethanol, toluene or dichloroethane. ##STR8##

The indoline derivatives are obtained by methods which are adapted fromthe literature. ##STR9##

Step 1 is carried out according to a procedure described in Katritzky etal., Tetrahedron 47:2683, 1991. The nitrosation of the amine (step 2) iscarried out by a reaction with sodium nitrite-hydrochloric acid and thereduction of the nitroso derivative (step 3) is carried out by thereaction of LiAlH₄ in THF (Fridman et al., Russian Chemical Reviews40(1):34.197. The last step of the synthesis (4) is carried out byreacting hydrazine with the appropriate ketone in an acidic medium, forexample, hydrochloric acid/ethanol or acetic acid (for a general reviewof this reaction one can consult Robinson "Fischer indole synthesis,"Wiley-Interscience, 1982.

In the case of applications of compounds according to the presentinvention, it should be noted that they can be used as a photochromicmaterial which is dispersed in the superficial part or in thecomposition of a polymer or mineral matrix. They can also be used insolution.

A photochromic solution can be obtained by dissolving the compound in anorganic solvent such as toluene, dichloromethane, tetrahydrofuran orethanol. The solutions obtained are, in general, colorless andtransparent. When exposed to sunlight, they developed a strongcoloration and their colorless state returns when they are placed in azone with less exposure to sunlight or, in other works, when they are nolonger exposed to UV radiation. In general, it is sufficient to use avery small concentration of product (on the order of 0.01-5%) to obtainan intense coloration.

The most intense applications are those in which the photochrome isdispersed uniformly within or on the surface of a polymer, copolymer ormixture of polymers. A great variety of methods of implementation can beconsidered. Those known to persons skilled in the art include, forexample, diffusion in the (co)polymer, from a suspension or solution ofthe photochrome, in a silicone oil, in an aliphatic or aromatichydrocarbon, in a glycol, or from another polymer matrix. The diffusionis routinely carried out at a temperature of 50-200° C. for a durationof 15 min to several hours, depending on the nature of the polymermatrix.

Another implementation technique consists in mixing the photochrome in aformulation of polymerizable substances, in depositing this mixture on asurface or in a mold and in then conducting the polymerization.

These implementation techniques and others are described in the articleby Crano et al. "Spiroxazines and their use in photochromic lenses"published by Applied Photochromic Polymer Systems, Published by Blackieand Son Ltd., 1992.

According to a variant of the invention, it is also possible to considergrafting the photochromes onto (co)polymers. Thus, another object of theinvention consists of (co)polymers to which at least one of thephotochromes described above has been grafted.

Examples of preferred polymer materials for the optical applications ofthe photochromic compounds according to the invention include thefollowing products:

alkyl, cycloalkyl, aryl or arylalkyl (mono, di, tri or tetra)polyacrylate of polymethylacrylate, optionally halogenated or comprisingat least one ether and/or ester and/or carbonate and/or carbamate and/orthiocarbamate and/or urea and/or amide group,

polystyrene, polycarbonate (e.g., bisphenol-A polycarbonate, allyldiethylene glycol polycarbonate), polyepoxy, polyurethane,polythiourethane, polysiloxane, polyacrylonitrile, polyamide, aliphaticor aromatic polyester, vinyl polymers, cellulose acetate, cellulosetriacetate, cellulose acetate-propionate or polyvinylbutyral,

copolymers of two or several types of monomer or mixtures of polymersmentioned above, preferably polycarbonate-polyurethane,poly)meth)acrylate-polyurethane, polystyrene-poly(meth)acrylate orpolystyrene-polyacrylonitrile, advantageously a mixture of polyester andof polycarbonate or of poly(meth)acrylate.

The quantity of photchrome used depends on the desired degree ofdarkening. Usually a quantity of 0.001-20 wt % is used.

The photochromic compounds according to the invention can be used aloneor in a mixture with other products to form a composition which can bein solid or liquid form, for example, in a solution or in a dispersion,as already indicated above. These compositions, which constitute anotherobject of the invention, can thus comprise the compounds (I), (I') ofthe invention and other complementary photochromic compounds which allowthe obtention of dark colorations, for example, gray or brown, which aredesired by the public in applications such as eyeglasses or shades.These complementary photochromic compounds have an λ_(max) and anabsorbance area surface in the visible such that, after association withthe compounds of the invention, an absorbance spectrum is obtained whichcovers the entire visible spectrum and which imparts the desired tint tothe mixture of activated photochromes.

The photochrome(s), which can be combined with the compounds of theinvention, is/are those known to a person skilled in the art anddescribed in the literature, for example, chromenes (U.S. Pat. Nos.3,567,605; 5,238,981; World Patent No. 9,422,850; European Patent No.0,562,915), spiropyrans or naphthospyropans [sic; naphthospiropyrans](U.S. Pat. No. 5,238,981) and spiroxazines (J. C. Crano et al., "AppliedPhotochromic Polymer Systems, " Publisher, Blackie & Son Ltd., 1992,Chapter 2).

These compositions according to the invention can also comprise:

nonphotochromic dyes which allow an adjustment of the tint,

and/or one or more stabilizers, such as, for example, an antioxidant,

and/or one or more anti-UV agents,

and/or one or more antiradical compounds,

and/or one or more deactivators of photochemical excitation states.

These additives can allow an improvement of the durability of saidcompositions.

According to another of its aspects pertaining to the application of thephotochromic compounds (I), (I'), the present invention also relates toophthalmic articles, such as eyeglass or sunshade articles, comprisingat least one compound according to the invention and/or at least one(co)polymer formed, at least in part, of recurrent units of type (I),(I') and/or at least one composition comprising the compounds (I), (I')according to the invention, as defined above, and/or at least onematrix, as defined above, made of an organic polymer material or of amineral material or of a mineral-organic hybrid material incorporatingat least one compound of the invention.

In practice, the articles which are more particularly referred to by thepresent invention are photochromic eyeglass lenses or shades, glarepartitions (windows for buildings, for locomotives, automobiles), theoptical devices, the decorative articles, the sun protection articles,the storage of data, etc.

The present invention will be understood better in the light of thefollowing examples of photochromic synthesis and validation of compounds(I), (I') and (I"), which it concerns.

EXAMPLES

Synthesis and properties of photochromic compounds (1)-(8) according tothe invention (Examples 1-8).

The formulas of compounds (1)-(8) are given below (see Table I).

Example 1: Synthesis of compound (1)

Step 1

Synthesis of 2-norbornylphenylamine

In a 250 mL flask equipped with a Dean-Start separator, the followingmixture is brought to reflux: 9.3 g of aniline, 12.1 g 2-norbornanone,13.2 g benzotriazole and 120 mL xylene. After 16 h, the mixture isreduced to dryness, then it is solubilized in 300 mL methanol, and theproduct is reduced with 6 g NaBH₄ at 50° C. for 1 h. The mixture is thenpoured into 200 mL water and the organic product is extracted with 3×100mL toluene. The organic phase is recovered, dried over magnesiumsulfate, and then reduced to dryness. In this manner, 20 g of thedesired amine are produced.

Step 2

Synthesis of 1-(2-norbornylphenyl)-1-phenylhydrazine

The amine from the preceding step (20 g) is suspended in 100 mL ofhydrochloric acid (1N), and then the mixture is maintained at 0° C. withstirring. An aqueous solution of NaNO₂ (7 g in 20 mL of water) is thenadded to the mixture in small portions. The temperature is then allowedto rise to the ambient temperature, and the nitroso derivative isextracted with 3×100 mL toluene. After evaporation of the solvent, 26 gof product are recovered. This product is then added slowly and in smallportions into tetrahydrofuran (200 mL) containing 7 g LiAlH₄ and, thenthe mixture is maintained at ambient temperature for 1 h. Subsequently,the mixture is cooled to 0° C., and then the excess hydride isneutralized with an aqueous sodium hydroxide solution. Next, 30 g Na₂SO₄ are added, and the organic phase is recovered by filtration andreduced to dryness. In this manner 21 g of the desired hydrazine areproduced.

Step 3 Synthesis of the 2-methyleneindoline derivative.

In a 100 mL flask, 21 g hydrazine from the preceding step and 8.6 g3-methyl-2-butanone in 100 mL ethanol containing 2 mL acetic acid at 50°C. are reacted. Then 15 mL of concentrated hydrochloric acid are addedand brought to reflux for 30 min. The mixture is then neutralized withsodium hydroxide to pH 10 and the indole derivative is extracted with3×100 mL isopropyl ether. After evaporation of the solvent, 17 g of thedesired product are prepared.

Step 4

Synthesis of spiroxazine (1)

The product from the preceding step (3 g) and 1.5 g 1-nitroso-2-naphtholare dissolved in 50 mL of absolute ethanol, and then the mixture isheated at 60° C. for 1 h. The mixture is then cooled to 0° C. After 30min, the precipitated product is recovered by filtration, and washedwith ethanol (20 mL). The solid is then recrystallized in ethanol. 820mg of the desired product are isolated after filtration. Its structureis confirmed by NMR spectroscopy and the latter reveals, in addition,the existence of two isomers (because of the end- or exo- position ofthe nitrogen on the norbornyl ring):

Example 2: Synthesis of compound (2)

The product from step 3 of Example 1 (2.6 g) and 1.9 g1-nitroso-2,7-dihydroxynaphthalene are dissolved in 130 mL ethanol, andthe mixture is brought to reflux for 5 h. The spiroxazine which ishydroxylated in the 9' position is isolated from the reaction mixture bychromatography on a silica column with a toluene/methanol mixture (9/1)as eluant. The methylation of the product is then carried out withdimethyl sulfate in acetone, in the presence of potassium carbonate andat 30° C. for 4 h. 1.8 g spiroxazine (2) are isolated after purificationby chromatography on a silica column with a toluene/heptane (1/1)mixture as eluent. Its structure is confirmed by NMR spectroscopy.

Example 3: synthesis of compound (3)

Compound (3) is synthesized in a similar manner to that of Example 1. InExample 1, 3,4-dimethylaniline is used instead of aniline. Steps 2 and 3lead to the indoline derivative, which is then condensed with1-nitroso-2-naphthol to yield spiroxazine 3. It is purified as above bychromatography on a silica column. Its structure is confirmed by NMRspectroscopy. The latter reveals the existence of a mixture of twodimethyl isomers (position 4,5 and 5,6 on the phenyl ring of theindole).

Example 4: Synthesis of compound (4)

Compound 4 is synthesized in a manner similar to that of Example 2. Instep 4, the indoline derivative prepared in Example 3 and1-nitroso-2,7-dihydroxynaphthalene are used. the intermediate obtainedis then methylated with dimethyl sulfate in acetone in the presence ofpotassium carbonate. The spiroxazine is purified as above by columnchromatography on silica. Its structure is confirmed by NMRspectroscopy.

Example 5: Synthesis of compound (5)

This compound is synthesized in a manner similar to that of Example 1,using as the starting product camphor instead of 2-norbornanone in step1 of the synthesis.

Example 6: synthesis of compound (6)

This compound is synthesized in a manner similar to that of Example 1,using as the starting product 3,4-dimethylaniline and camphor in step 1of the synthesis.

Example 7: Synthesis of compound (7)

This compound is synthesized in a manner similar to that of thepreceding example with 3,5-dimethylaniline instead of3,4-dimethylaniline in step 1 of the synthesis.

Example 8: Synthesis of compound (8)

This compound is synthesized in a manner similar to that of the Example3 with 3-methyl-2-pentanone instead of 3-methyl-2-butanone in step 3 ofthe synthesis.

Applications

Example 9: Incorporation of compounds (1) through (8) in a polyacrylate

General procedure: 10 mg of each one of compounds (1) through (8) aredissolved in tetraethoxylated bisphenol A dimethyl methacrylate,marketed under the name DIACRYL 121 by the company AKZO) and alsocontaining 40 mg 2',2'-azobis(2-methylbutyronitrile). The solution isthen degassed, rendered inert with argon and then poured into a glasslens mold having a diameter of 8 cm and a thickness of 2 mm. The mold isthen placed in an oven at 70° C. for 12 h. After removal from the mold,a transparent and rigid lens is obtained. When exposed to solarradiation, the glass quickly develops an intense blue coloration and itbecomes colorless again in darkness. The photochromic characteristicsare given in Table I below. For comparison, the characteristics ofcompounds C1, C2, C3, C4 and C5 of the prior art are also given in TableI below.

Table I

Legends

λ_(max) measured in D121 in a thickness of 2 mm with exposure to a xenonlamp, 60,000 lx, at 22° C.,

T0=initial transmission (inactivated state) measured at λ_(max),

TD15=transmission after 15 min of exposure measured at λ_(max),

IOD=Induced optical density {log(T0/TD15)},

R5=% of recovery of the initial transmission after 5 min ofdecoloration,

(Y0/Y15)_(0h) =initial integrated transmission and transmission after 15min of exposure, respectively, and before ageing,

Y0/YD15)_(300h) =initial integrated transmission and transmission after15 min of exposure after 300 h of ageing under an exposure to 60,000 lx.

                                      TABLE I                                     __________________________________________________________________________                                 Proportion                                                                         .sub.max                                                                         T0                                                                              TD15  R5                                                                              (Y0/YD15).sub.0h                 Compound structure % nm % % DOI % (Y0/YD15).sub.300h                        __________________________________________________________________________      Ex. 1                                                                                                                        0.1 612 90 35 0.41 82                                                       90/57  89/56                      - Ex. 2                                                                                                                     0.1 608 89 23 0.59 77                                                       89/42  89/40                      - Ex. 3                                                                                                                     0.1 624 91 9 0.99 65                                                        90/39  87/38                      - Ex. 4                                                                                                                     0.1 618 91 8 1.08 67                                                        91/32  88/28                      - Ex. 5                                                                                                                     0.1 616 88 15 0.77 67                                                         - Ex. 6                                                                       0.1 624 88 0.5 2.25 35                                                      88/18  86/24                      - Ex. 7                                                                                                                     0.1 616 89 1.0 1.95 22                                                      89/17 22                          - Ex. 8                                                                                                                     0.1 622 89 2.3 1.59 36                                                      89/26  87/29                      - C1                                                                                                                        0.1 604 90 39 0.36 83 --        - C2                                                                                                                        0.1 610 86 22 0.59 74                                                       86/44  86/43                      - C3                                                                                                                        0.1 616 86 18 0.69 68 --        - C4                                                                                                                        0.1 624 91 17 0.73 70                                                       91/48 40                          - C5                                                                                                                        0.1 620 81 19 0.53 63                                                       85/48  83/47                   __________________________________________________________________________

A comparison of the properties of Examples 1, 2 and 5 and of ComparativeExamples C₁ and C₂, on the one hand, and Examples 3, 4 and 6 andComparative Examples C₃ -C₅, on the other hand, show that the compoundsof the prior art with similar structure but without the polycyclic groupaccording to the invention do not possess the advantageous combinationof properties sought. In particular, it can be observed that thecompounds of the invention have a better compromise between low initialcoloration and strong induced optical density, and are photochemicallyvery stable with little or no loss of colorability or decrease of theinitial transmission.

I claim:
 1. Photochromic compounds having the following general formula(I): ##STR23## in which, R¹ is a polycyclic group formed by at least onealicyclic group linked to bridged or condensed with at least one otheraliphatic and/or aromatic ring, where the rings can optionally containat least one heteroatom and at least one unsaturation,R² and R³ areidentical or different and represent an alkyl group, straight orbranched, of 1-12 carbon atoms, an alkenyl group, an alkynyl group, anaryl group, an alkylaryl group, or a cycloalkyl group, or R² and R³combine to form a carbocyclic or heterocyclic group having 5 to 10atoms, R⁴, R⁵, R⁶, and R⁷ are identical or different andrepresent:hydrogen, an alkyl group, a cycloalkyl group, an alkenylgroup, an alkynyl group, an aryl group, a heteroaryl group, an aryloxygroup, or an aralkyl group, said group being optionally halogenated, ahalogen, OR, SR, --OCOR, or --COOR, wherein R is H, alkyl and/orcycloalkyl and/or aryl, a (poly)ether, a (poly)amide, a (poly)carbonate,a (poly)carbamate, a (poly)urea, or a (poly)ester, * an amino radicalwhich gives rise, once it is bound in (I), to a primary, secondary, ortertiary amine, said amine being alkyl, aryl, or aralkyl, mono- ordisubstituted, or * an aminocyclic radical containing, optionally, oneor more heteroatoms, or an election withdrawing group, where at leasttwo of the radicals R⁴, R⁵, R⁶, and R⁷ can optionally form an assemblyof at least one aromatic ring having 5 or 6 members or aliphatic ringhaving 5 to 7 members, said ring(s) comprising, optionally, at least oneheteroatom, so as to form at least one heterocyclic ring, the latterbeing optionally substituted by one or more radicals, identical ordifferent, and having the same definition as given above for R⁴ to R⁷, Arepresents an aromatic or heteroaromatic ring optionally substituted byone or more radicals R⁸, which are identical or different and which havethe same definition as given above for R⁴ to R⁷, and n is a wholenumber, and, when n≧2, two of the radicals R⁶ can optionally combine toform at least one aromatic or heteroaromatic ring.
 2. Compoundsaccording to claim 1, characterized in that the polycyclic group R¹ is abicyclic group.
 3. Compounds according to claim 2, characterized in thatthe bicyclic group is asymmetric.
 4. Compounds according to claim 1,characterized in that R¹ is selected from the following groups:##STR24##
 5. Compounds according to claim 1, characterized in that thegroup R¹ is a substituted or unsubstituted norbornyl group. 6.Photochromic compounds having the following general formula (I'): inwhich,R¹ is a polycyclic group formed by at least one alicyclic grouplinked to ridged or condensed with at least one other aliphatic and/oraromatic ring, where the rings can optionally contain at least oneheteroatom and at least on unsaturation, R² and R³ are identical ordifferent and represent an alkyl group, straight or branched, of 1-12carbon atoms, an alkenyl group, an alkynyl group, an aryl group, analkylaryl group, or a cycloalkyl group, or R² and R³ combine to form acarbocyclic or heterocyclic group having 5 to 10 atoms, R⁴, R⁶, and R⁷are identical or different and represent:hydrogen, an alkyl group, acycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, aheteroaryl group, an aryloxy group, or an aralkyl group, said groupbeing optionally halogenated, a halogen, OR, SR, --OCOR, or --COOR,wherein R is H, alkyl and/or cycloaklyl and/or aryl, a (poly)ether, a(poly)amide, a (poly)carbonate, a (poly)carbamate, a (poly)urea, or a(poly)ester, * an amino radical which gives rise, once it is bound in(I'), to a primary, secondary, or tertiary amine, said amine beingalkyl, aryl, or aralkyl, mono- or disubstituted, or * an aminocyclicradical containing, optionally, one or more heteroatoms, or an electionwithdrawing group, where the radicals R⁶ R⁷ can optionally form anassembly of at least one aromatic ring having 5 or 6 members oraliphatic ring having 5 to 7 members, said ring(s) comprising,optionally, at least one heteroatom, so as to form at least oneheterocyclic ring, the later being optionally substituted by one or moreradicals, identical or different, and having the same definition asgiven above for R⁴, R⁵, and R⁷, A represents an aromatic orheteroaromatic ring optionally substituted by one or more radicals R⁸,which are identical or different and which have the same definition asgiven above for R⁴, R⁵, and R⁷, n is a whole number, and, when n≧2, twoof the radicals R⁸ can optionally combine to form at least one aromaticor heteroaromatic ring, and B is an aromatic or aliphatic ring having 5to 7 members.
 7. Photochromic compounds according to claim 1,characterized in that they have the following general formula (I"):##STR25## in which R¹ -R⁴ and R⁶ -R⁸ are defined as in claim 1, and nand m have values from 0 to
 4. 8. Compounds according to claim 1,characterized in that the groups R¹ -R⁹ of formula (I) according to theinvention comprise and/or form at least one reactive polymerizationand/or cross-linking group selected from the following: alkenyl,methacroyl, acroyl, acryloxyalkyl, methacryloxalkyl, and epoxy. 9.Compounds according to claim 1, characterized in that they present thefollowing formula: ##STR26## where N--R¹ is selected from the followinggroup of formulae: ##STR27##10.
 10. (Co)polymer and/or crosslinkage,obtained by the polymerization and/or crosslinking of at least onemonomer consisting of at least one photochromic compound according toclaim
 8. 11. (Co)polymer, characterized in that it is grafted with atleast one photochromic compound according to claim
 1. 12. Photochromiccomposition, characterized in that it comprises: at least one compoundaccording to claim 1, andoptionally at least one other photochromiccompound and/or at least one dye and/or at least one stabilizer. 13.(Co)polymer matrix, characterized in that it comprises:at least onecompound according claim
 1. 14. Matrix according to claim 13,characterized in that the (co)polymer is selected from the followinglist:alkyl, cycloaklyl, aryl, or arylalkyl (mono, di, tri, or tetra)polyacrylate or polymethacrylate optionally halogenated or comprising atleast one ether and/or ester and/or carbonate and/or carbamate and/orthiocarbamate and/or urea and/or amide group, polystyrene,polycarbonate, polyepoxy, polyurethane, polythiourethane, polysiloxane,polyacrylonitrile, polyamide, aliphatic or aromatic polyester, polyvinylacetate, cellulose acetate, cellulose triacetate, cellulose acetatepropionate, or polyvinylbutyral, and copolymers of two or more types ofmonomer or mixtures of the monomers indicated above.
 15. Ophthalmic orsolar article comprising:at least one compound according to claim
 1. 16.Article according to claim 15, characterized in that it consists of alens.
 17. Glass partition and/or optical device comprising:at least onecompound according to claim
 1. 18. Photochromic compound according toclaim 6, characterized in that B comprises a heteroatom which issubstituted by one or more radicals.
 19. Photochromic compound accordingto claim 18, characterized in that the radicals have the same definitionas R⁴ to R⁷.
 20. (Co)polymer, characterized in that it is grafted withat least one photochromic compound according to claim
 6. 21.Photochromic composition, characterized in that it comprises:at leastone compound according to claim 6, and optionally at least one otherphotochromic compound and/or at least one dye and/or at least onestabilizer.
 22. (Co)polymer matrix, characterized in that itcomprises:at least one compound according to claim
 6. 23. Matrixaccording to claim 22, characterized in that the (co)polymer is selectedfrom the following list:alkyl, cycloalkyl, aryl, or arylalkyl (mono, di,tri, or tetra) polyacrylate or polymethacrylate optionally halogenatedor comprising at least one ether and/or ester and/or carbonate and/orcarbamate and/or thiocarbamate and/or urea and/or amide group,polystyrene, polycarbonate, polyepoxy, polyurethane, polythiourethane,polysiloxane, polyacrylonitrile, polyamide, aliphatic or aromaticpolyester, polyvinyl acetate, cellulose acetate, cellulose triacetate,cellulose acetate propionate, or polyvinylbutyral, and copolymers of twoor more types of monomer or mixtures of the monomers indicated above.24. Ophthalmic or solar article comprising:at least one compoundaccording to claim
 6. 25. Article according to claim 24, characterizedin that it consists of a lens.
 26. Glass partition and/or optical devicecomprising:at least one compound according to claim
 6. 27. Photochromiccomposition, characterized in that it comprises:at least one (co)polymeraccording to claim 10 and optionally at least one other photochromiccompound and/or at least one dye and/or at least one stabilizer. 28.Photochromic composition, characterized in that it comprises:at leastone (co)polymer according to claim 11 and optionally at least one otherphotochromic compound and/or at least one dye and/or at least onestabilizer.
 29. Photochromic composition, characterized in that itcomprises:at least one (co)polymer according to claim 20 and optionallyat least one other photochromic compound and/or at least one dye and/orat least one stabilizer.
 30. (Co)polymer matrix, characterized in thatit comprises:at least one (co)polymer according to claim
 10. 31. Matrixaccording to claim 30, characterized in that the (co)polymer is selectedfrom the following list:alkyl, cycloalkyl, aryl, or arylalkyl (mono, di,tri, or tetra) polyacrylate or polymethacrylate optionally halogenatedor comprising at least one ether and/or ester and/or carbonate and/orcarbamate and/or thiocarbamate and/or urea and/or amide group,polystyrene, polycarbonate, polyepoxy, polyurethane, polythiourethane,polysiloxane, polyacrylonitrile, polyamide, aliphatic or aromaticpolyester, polyvinyl acetate, cellulose acetate, cellulose triacetate,cellulose acetate propionate, or polyvinylbutyral, and copolymers of twoor more types of monomer or mixtures of the monomers indicated above.32. (Co)polymer matrix, characterized in that it comprises:at least one(co)polymer according to claim
 11. 33. Matrix according to claim 32,characterized in that the (co)polymer is selected from the followinglist:alkyl, cycloalkyl, aryl, or arylalkyl (mono, di, tri, or tetra)polyacrylate or polymethacrylate optionally halogenated or comprising atleast one ether and/or ester and/or carbonate and/or carbamate and/orthiocarbamate and/or urea and/or amide group, polystyrene,polycarbonate, polyepoxy, polyurethane, polythiourethane, polysiloxane,polyacrylonitrile, polyamide, aliphatic or aromatic polyester, polyvinylacetate, cellulose acetate, cellulose triacetate, cellulose acetatepropionate, or polyvinylbutyral, and copolymers of two or more types ofmonomer or mixtures of the monomers indicated above.
 34. (Co)polymermatrix, characterized in that it comprises:at least one (co)polymeraccording to claim
 20. 35. Matrix according to claim 34, characterizedin that the (co)polymer is selected from the following list:alkyl,cycloaklyl, aryl, or arylalkyl (mono, di, tri, or tetra) polyacrylate orpolymethacrylate optionally halogenated or comprising at least one etherand/or ester and/or carbonate and/or carbamate and/or thiocarbamateand/or urea and/or amide group, polystyrene, polycarbonate, polyepoxy,polyurethane, polythiourethane, polysiloxane, polyacrylonitrile,polyamide, aliphatic or aromatic polyester, polyvinyl acetate, celluloseacetate, cellulose triacetate, cellulose acetate propionate, orpolyvinylbutyral, and copolymers of two or more types of monomer ormixtures of the monomers indicated above.
 36. Ophthalmic or solararticle comprising:at least one (co)polymer according to claim
 10. 37.Article according to claim 36, characterized in that it consists of alens.
 38. Ophthalmic or solar article comprising:at least one(co)polymer according to claim
 11. 39. Article according to claim 38,characterized in that it consists of a lens.
 40. Ophthalmic or solararticle comprising:at least one (co)polymer according to claim
 20. 41.Article according to claim 40, characterized in that it consists of alens.
 42. Glass partition and/or optical device comprising:at least one(co)polymer according to claim
 10. 43. Glass partition and/or opticaldevice comprising:at least one (co)polymer according to claim
 11. 44.Glass partition and/or optical device comprising:at least one(co)polymer according to claim 20.